All Services: I signed up and got the following message: 'No vulnerabilities were found and the host did not respond to any of our checks' - what does this mean?

This can mean one of two things.

Either:

1) The host is currently unreachable. It could be that the host is unreachable because of a problem with your server. Quite often, however, it is because your firewall is denying access to the HackerGuardian scanner. In order for the HackerGuardian scan to be successful your firewall must be set to allow the IP address the scan is coming from. The IP ranges that we scan from are 199.66.200.32/28 and 91.209.196.32/28.